The present invention broadly relates to a manual force-multiplying device and, more specifically, pertains to a new and improved construction of a lever-actuated tong device.
Generally speaking, the lever-actuated tong device of the present invention is of the type comprising two operating or actuating handles pivotable about a central pivot or pivot pin. Mounted at each operating handle, by means of a further pivot or pivot pin, is a respective jaw or pivotal lever. Both of the jaw levers are pivotably mounted in a fixed relation to one another about at least one pivot pin.
Such type of tong devices comprise moveable mutually closing jaws actuated by means providing a double-levered action. Such tongs are particularly employed as bolt-cutting pliers or as seal-clamping pliers in which the pivoting motion of the manually operated handles is relatively greatly multiplied in order to attain a relatively large closing force at the jaws.
To fulfill increased force requirements with a given size of tong head, it is not sufficient merely to lengthen the operating or actuating handles since the pivots would then be overloaded. It is also then necessary to reinforce the pivots. This means that the lever-actuated tong device tends to become larger and more inconvenient to handle.